An emergencies ministry member walks at the site of a Malaysia Airlines Boeing 777 plane crash near the settlement of Grabovo in the Donetsk region on July 17, 2014. -- PHOTO: REUTERS

By Ong Sor Fern

What could have brought down MH17?

Media reports have been circling around a Soviet-era missile system, created in the 1970s, as the possible culprit.

Airliners typically cruise at about 30,000 ft (9.1km), so it would take a sophisticated missile system to bring it down. The Washington Post reported that it is unlikely that a man-portable air-defense systems, known as manpads, could be responsible. It quoted a former Marine Special Operations member who trained in air defense systems as saying: "A manpads' original purpose is for low-flying aircraft with high-heat signatures.”

Military expert IHS Jane's Missiles & Rockets editor Doug Richardson also dismissed manpads as a possible cause, adding that the airliner's cruising height "would be well above the coverage of shoulder-fired man-portable missile systems, which typically can engage targets flying at up to around 10,000 ft".

Mr Richardson noted that two mobile surface-to-air missile systems in use in the Ukraine have the capacity to shoot down an airliner. They are a Kub, also known to the West as the SA-6 Gainful, or the Buk, also called known the SA-11 Gadfly in the West.

He said: "The Kub can cope with targets flying at up to 26,000 ft (8,000m), so cannot reach the reported cruise height of the airliner. Buk coverage extends up to 72,000 ft (22,000m). Its maximum range is 32km."

Since the 1970s, the Buk system has been upgraded. The current version is the SA-17 Buk 2, also known to NATO countries as the Grizzly. While armed forces in the region may not have the latest version, there have been reports of the SA-11 system spotted in the area. Equipped with radar and four missile launchers, it can fire missiles that reach up to 22km in altitude. MH17 was reportedly cruising at an altitude of 10km, well within the system's range.

A Buk battery includes radar, a command post vehicle as well as launchers which are each armed with four radar-guided missiles. There were incidents in the past week with two Ukrainian planes being downed by missiles, including one that was hit by a ground-launched missile.